Geotechnical Assessment for Deep Foundation of Overpasses at Hazara Expressway, Haripur, Pakistan (P-0972) (MFN 5851)

Abstract

The purpose of the study is to carryout geotechnical assessment for deep foundations of five overpasses at 20 km segment of an expressway in Haripur, KPK. Rocks of Pre-Cambrian to middle Eocene’s age are dominant in the study area. Subsurface exploration, soil sampling and laboratory analysis were incorporated for geotechnical design of the flyovers. Rotary drilling and Percussion boring methods were adopted for bore holes drilling and disturbed/undisturbed soil samples were considered in terms of the proper handling, transportation, and storage of soil samples for laboratory testing. In-situ tests, i.e. Standard penetration, Cone Penetration, Bulk Density and Moisture Content were performed. Laboratory index, shear strength, and stiffness testing was executed in complement to the field testing program. Geotechnical interpretations were made by correlating the engineering properties from the acquired field and lab measurements. Using soil strength parameters (soil consistency, grain size distribution, shear strength, uniaxial compressive strength, bulk densities, in situ moisture content, resistance against penetration) allowable bearing capacities for deep foundations (Pile) were determined in cohesive and non-cohesive soil against pile length at different diameters (760 mm, 900 mm & 1200 mm) using Meyerhof method for estimating ultimate load bearing capacity (Qu). The values of allowable load for the fraction piles varies from 153.0 - 209.0 Tons by keeping the diameter 1200 mm and embedded length of the pile 30.0 m constant below from the Existing Ground Level (EGL).